﻿<!Doctype html>
<html>
    <head>
        <meta charset="utf-8" />
        <title>html5 image to base64</title>
    </head>
    <body>
        <script type="text/javascript">
        window.onload = function(){ 
        // 抓取上传图片，转换代码结果，显示图片的dom
        var img_upload=document.getElementById("img_upload");
        var base64_code=document.getElementById("base64_code");
        var img_area=document.getElementById("img_area");
        // 添加功能出发监听事件
        img_upload.addEventListener('change',readFile,false);}
        function readFile(){
            var file=this.files[0];
            if(!/image\/\w+/.test(file.type)){ 
                alert("请确保文件为图像类型"); 
                return false; 
            }
            var reader=new FileReader();
            reader.readAsDataURL(file);
            reader.onload=function(){
                base64_code.innerHTML = this.result; 
                img_area.innerHTML = '<div>图片img标签展示：</div><img src="'+this.result+'" alt=""/>'; 
            }
        }
        </script>
        <input type="file" id="img_upload"/>
        <textarea id="base64_code" rows="30" cols="360"></textarea>
        <p id="img_area"></p>
    </body>
</html>

